The present invention is directed to a method and apparatus for positioning insulated concrete forms when forming the building footer or base and the walls of a building.
The use of cements and concretes as structural materials to construct a building is well known. For example, cements and concretes may be used to form footers, walls, floors and other structural elements of a building. Cement and concrete materials may be formed in a wide variety of shapes and forms since they may be provided in a liquid, semi liquid, or slurry state and poured into a form where they harden and cure in place to form a permanent structural element. The strength of the concrete element may be readily increased with the use of readily available reinforcing elements, such as metal bars and mesh. The reinforcing elements are positioned in the form prior to pouring the cement into the form so that the reinforcing elements become part of the permanent structural cement element.
A wide variety of concrete forms have been used. Perhaps the most commonly used form is made of wood, metal or a combination of those materials. For example, when pouring a footer, which supports a building, a trench is dug around the outer perimeter of the building to be constructed. Forms are then positioned in the trench so that they extend upwardly from the bottom of the trench to receive the concrete slurry between the forms where the concrete may harden. Before pouring the concrete into the footer form, the forms are carefully leveled so that the top of the footer is level and provides a surface on which the walls of the building may be constructed.
After this leveling process, the forms are secured in position to resist movement of their forms when the concrete is poured into and worked between the forms. A variety of devices may be used to secure the forms in position such as stakes, metal tie plates, or metal tie rods between the opposing forms. Reinforcing elements such as metal bars, are then positioned between the opposing forms and spaced upwardly from the bottom of the trench to impart additional strength to the footer. One known reinforcing rod support is a pyramid shaped wire form with the base resting on the bottom of the trench and the apex holding the reinforcing bar at a specific distance above the bottom of the trench. After the cement is poured, and while in a liquid or semi liquid state, the cement is worked to avoid air pockets within the footer and also provide a smooth and level upper footer surface.
The top of the footer is defined by the upper footer surface and provides for supporting the walls of the building. A common construction technique is to construct a concrete block wall on the top of the footer. Another construction technique is disclosed in Gagnon, U.S. Pat. No. 6,540,201, which provides for a tilt up concrete panel forming system. A concrete wall is preformed and a base strip is positioned on the supporting surface and the preformed concrete wall is then tilted up into position and held in that position by the brackets and the base strip.
Mandish, U.S. Pat. No. 5,555,698, provides a building panel having a mesh surface for supporting a lightweight concrete coating with the building panel filled with insulation material. Shamash, U.S. Pat. No. 4,612,744, utilizes a buried anchoring pod and pilings extending upwardly from the pods for supporting the building. The walls of the building are formed by a concrete poured into a plastic U-shaped base member with wall panels extending upwardly from the base member. When concrete is poured into the base member and wall panels, the wall of the building is formed.
Another building technique is described in Franklin, U.S. Pat. No. 5,924,254. Franklin describes the use of the modular construction system using wall units of precast concrete which are stacked on the top of the footer to create a wall. The wall units receive reinforcing bar extending upwardly from the top of the footer and a spacer/tensioning assembly is provided. Grout is then poured into the vertically and horizontally extending passages of the wall unit to create a monolithic wall.
Yet another wall forming system is described in VanderWerf, U.S. Pat. No. 6,698,710, which provides for the use of panels, including insulating foam panels, and substantially rigid panels of wood, plastic, polymeric composites, cementitious composites of foam, fibers, metal and other such materials, many of which provide additional insulating properties. Wall tie rail and corner tie rail components and other such components are provided to form wall sections for mounting on the footer.
An alternative to wall forming systems using conventional wood and metal forms, provides for the use of preformed expanded polymeric foam forms, commonly referred to as Insulating Concrete Forms or “ICF”. While there are many types of ICF forming systems, in general, hollow blocks or panels molded or manufactured from low density polymeric foam materials are positioned on the foundation or footer and stacked vertically to form a wall or a portion of a wall. Liquid concrete or cement is poured into the hollow portions of the ICF blocks or panels to form a wall or portion of a wall. After the concrete hardens, the ICF blocks or panels are left in place and provide enhanced insulating for the building walls, reduced moisture passage through the walls, provide a substrate into which utility lines and typing can be installed and provide a service for the attachment of finishing materials.
One ICF is described in Berrenberg, U.S. Pat. No. 4,879,855, and has a central portion of expanded webbed steel with its opposite sides terminating in metal strips. The Berrenberg ICF is formed from an expanded polymeric foam, such as polystyrene, with the expanded webbed steel extending between the outside surfaces of the ICF. The metal strips are provided on the outside surfaces of the ICF to provide for attaching finishing materials to the outer surfaces of the ICF. In facilitating the construction of a building, a footer is poured and allowed to hardened with a flat and level top. When pouring a footer it is difficult to maintain the top of the footer level around the periphery of the building. When there are slight variances in the level of the top of the footer some portions will be higher than other portions.
The top of the footer is then cleaned and polyurethane foam adhesive is applied to the bottom of the ICF form. The bottom of the ICF form is then positioned on and secured to the top of the footer with the polyurethane foam adhesive. On occasion, the ICF form shifts or moves while it is being secured to the top of the footer with adhesive and the wall is misaligned. The variances in the level of the top of the footer allow for variances in the level of the ICF forms. Any slight shifting of the ICF forms when they are secured to the top of the footer also allow further variances. Additional ICF forms are secured to the bottom ICF forms attached to the top of the footer and the variances in the level of the ICF forms are continued and may be accentuated.
Alternatively, the ICF forms may be set on the footer when the footer concrete is wet. This technique of positioning the first course of ICF forms requires constant adjustment to level the forms while also maintaining them in alignment along the wall. Since the concrete is still in a fluid or semi fluid state it is difficult to properly change and adjust the alignment and level of the entire bottom course of the ICF forms.
Another alternative in mounting the ICF forms to the top of the footer includes the use of steel brackets made from sheet metal. The steel brackets are mounted on the top of the footer with the ICF form glued to the top of the footer with its alignment maintain by the steel brackets.
While the ICF form described in Berrenberg is used herein in describing the present invention, it should be understood that any other ICF form may be used in conjunction with the present invention.
For example, Hartling, U.S. Pat. No. 5,367,845, describes another ICF form with a footing block system and a wall form system. The footing block system provides opposing shells of expanded polymeric foam for forming a footer. The wall form system provides for the use of ICF block forms positioned on the footing block system with complex geometry to interlock the components of the both the wall and footing form systems. Hartling also provides a reinforcing bar support in the footing block system. Holland, U.S. Pat. No. 5,086,600, provides interlocking surfaces on the blocks for maintaining alignment between the blocks.
It is desirable to provide a building using ICF forms with at least the first course of ICF's formed integrally with the footer so as to avoid movement of the ICF forms on the top of the footer which would create misalignment of the walls formed by the ICF forms. Furthermore, by forming at least the first course of ICF's integrally with the footer, the level and alignment of the first course of concrete forms is accomplished without requiring the precise leveling and alignment of the footer.
It is also desirable to provide a building using ICF forms which minimizes the possibility of water leakage between the bottom course of the ICF forms and the footer. By minimizing such leakage, the likelihood of water flowing inside the basement or the inside of the ICF forms is decreased.
An important factor in constructing a building is the cost of construction. Labor constitutes a substantial cost in constructing a building. The placement of ICF forms using known construction techniques is labor-intensive when properly aligning the ICF forms on the top of the footer and also assuring that they are level through out the length of the wall or walls to be formed by the ICF forms.
When the bottom of the ICF form is positioned on and secured to the top of the footer with polyurethane foam adhesive, if differing thicknesses of adhesive are placed on the bottom of the ICF form, the ICF form may be tilted or canted in a variety directions and not be properly aligned with each other or the footer. Also, even if a consistent amount of polyurethane foam is applied to the bottom of the ICF form, if a greater amount of pressure is exerted on one portion of the ICF form when positioning it on the top of the footer, the ICF form will be tilted or canted. Any slight shifting of the ICF forms when they are secured to the top of the footer also allow further variances. This construction technique requires substantial labor in aligning the ICF forms along the top of the footer and also placement of the ICF forms so they are not canted or tilted with respect to the top of the footer. Resolving these numerous variables is labor intensive.
Another known construction technique in the placement of ICF forms on the footer, is to set the ICF forms on the top of the footer when the footer concrete is wet. This technique of positioning the first course of ICF forms requires constant adjustment to level the forms while also maintaining them in alignment along the wall. Since the concrete is still in a fluid or semi fluid state is difficult to properly change and adjust the alignment and level of the entire bottom course of the ICF forms. Once again, this technique requires substantial labor.
Yet another known construction technique in the placement of ICF forms on the top of the footer is to mount steel brackets on the top of the footer with the ICF form glued to the top of the footer with the alignment of the ICF form maintained by the steel brackets. This construction technique requires the proper positioning of the steel brackets on the top of the footer and then securing the brackets to the footer by threaded fasteners and the like. If the top of the footer is not level, the brackets are not level and must be leveled, such as by the use of shims or the like, before the ICF forms are positioned on the top of the footer.
Further, it is desirable to provide for the use of ICF forms of different sizes. This allows the building wall to be formed in different thicknesses and configurations depended on the requirements of each specific structure or building.